1. Field of the Invention
The present invention relates generally to image processing, and more particularly, to a method for high dynamic range imaging.
The objective of high dynamic range imaging is to capture, represent and display the significant amount of luminance variation of the real-world scenes. This problem commonly arises from the limited dynamic range capability of current imaging devices, compared to the much wider perception range of the human visual system. Since the HDRI is aimed to span a large luminance range for vivid image representation and reproduction, it has many applications on, for example, cinematography, photography, computer graphics and visualization, etc.
In addition to the increasing demand of high quality reproduction of real-world scenes, there is always a need for stereoscopic image representation for the binocular human visual system. The objective is to provide us the depth perception ability using stereo image disparities. Thus, there are many advantages and a large application domain available from combining HDRI with stereo vision. For example, the so-called DIBR (depth image based rendering) can be used to generate the content of 3D TV, video games, augmented reality, or used for advanced video surveillance.
2. Description of the Related Art
The most intuitive way of capturing HDR images is to adopt special light detecting sensors capable of recording images with extended intensity range. However, commercially available HDRI systems are usually very expensive and still only accessible to the professional users. For this reason, many researchers have proposed various HDRI techniques using low-cost imaging devices
U.S. Pat. No. 6,864,916 entitled an apparatus and a method for synthesis of high dynamic range imaging disclosed that an image sensor is provided for sequentially capturing multiple images of one scene with different exposures and then combining the multiple images to synthesize a single high dynamic range image.
Taiwan Patent No. I246031 entitled a system and a method for synthesis of images having multiple exposures, based on the above patent, disclosed that an image sensing unit is provided for sensing at least one low dynamic range image, which is the image of the same scene in different exposure time; and an image synthesis unit coupled with the image sensing unit and setting up an exposure history of low dynamic range image for synthesizing the low dynamic image by reference to the exposure history to create a synthetic high dynamic range image. Since each of the low dynamic range images captured by this approach is not done at the same time spot, however, the low dynamic range images are inconsistent with one another to incur afterimage or ghost image in the synthetic high dynamic range image.